The invention relates to devices for assisting in the identification and location of persons in distress, particularly those in heavy fog or smoke.
Many firemen have lost their lives or been seriously injured because they became trapped, injured or disoriented in a burning structure and their comrades either did not know they were in distress or could not find them quickly.
Several devices have been developed to aid in this problem. Self-contained units that emit sound and/or light in an emergency have been employed. These include devices that emit a loud alarm when the device senses no movement for a period of time.
These devices have their own batteries and are meant to attach to the fireman's helmet, clothing or breathing apparatus.
None of these devices offer much help for the fireman who becomes incapacitated out of the hearing/visual range of these devices. By the time the firemen is missed, it may be too late.